Maybe the most unusual thing about Robin Williams’ tragic death was that it didn’t involve drugs or alcohol. So many celeb deaths have featured both.

Philip Seymour Hoffman , who died earlier this year, apparently accidentally, had heroin, cocaine, benzodiazepine tranquilizers and amphetamines in his system. There were a number of other medications found in his apartment, including the addiction treatment drug buprenorphine.

Peaches Geldof, the daughter of Live Aid founder Bob Geldof, died this summer from an overdose of codeine, morphine, and methadone. Heroin was also found on the premises, suggesting use of that drug as well. Her family said she’d been hoping to taper off methadone following an extended maintenance.

Heath Ledger, who gained fame as the Joker in a Batman movie and also in the film Brokeback Mountain, died “as the result of acute intoxication by the combined effects of oxycodone (Oxycontin), hydrocodone, diazepam (Valium), temazepam (Restoril), alprazolam (Xanax), and doxylamine (an over the counter antihistamine with strong sedative effects),” according to the medical examiner.

No question that combining or ‘stacking’ these substances, illegal and/or prescription, increases the risk for unintended OD. But I admit I wonder who’s prescribing them (if indeed they were prescribed) to known users. And what controls were implemented, if any.

Probably not much.

Alcoholics still die of alcohol poisoning, of course. Amy Winehouse’s death apparently came on the heels of a three day binge following a month of abstinence. Her father told the press she hadn’t taken drugs for three years, but was prone to serious alcohol binges. “This was someone who was moving towards abstinence,” he added. “But unfortunately, she didn’t quite make it.”

Somebody went to the trouble of compiling a list of notables who suffered similar fate.